El Nino Watch
Island stores let you buy today. Lazada and Shopee do deliver to Samui, but most parcels cross by ferry and take longer than to the mainland; when rough seas stop the ferries, deliveries stop too. Buy before a storm, not during it.
Preparedness
On the island (checked 2026-09-24): Global House in Maenam (tanks, jerrycans, tarps, rope, boots, fans), Makro and HomePro in Bophut, Big C in Bophut, several Lotus's (Chaweng, Lamai...), and Boots at Central Samui in Chaweng, plus local pharmacies. The panel gives a map search for each; stock is not checked, so call before a special trip.
Online: Lazada and Shopee deliver to Koh Samui. Delivery usually takes longer than to Bangkok because parcels cross by ferry; the estimate is shown at checkout. Specialist items (0.1 micron filters, crank radios, purification tablets) are often online only.
Before a storm: order online weeks ahead in the calm season; in the days before a forecast storm buy locally; once ferries are cancelled, assume no parcel will arrive.
Rough seas in the northeast monsoon (October-January) stop ferries, and with them shop restocking and parcel deliveries. Stock bought early is the only stock you can count on.